In this article, a novel two-mode operation concept for the THz oscillator with the folded waveguide is proposed. To demonstrate this concept, a two mode 4π band-edge oscillator has been simulated and fabricated. The simulation predicted that the designed oscillator was capable of delivering maximal output power of over 2 W at 301.7–303 GHz for both forward and backward operation mode. On the other hand, the testing data showed that the first prototype of the two-mode oscillator was able to produce output power over 1 W at about 305.6 GHz (voltage 23.04 kV) and 1.51 W at 308.8 GHz (voltage 24.33 kV), for forward and backward operation mode, respectively, with a 5–7 GHz frequency shift compared to the simulation. The findings demonstrate the correctness of the proposed two-mode concept for developing novel two-mode band-edge oscillators. There exist some inconsistencies between the testing and simulation, which will be discussed in the article. It is believed that the proposed two-mode concept is useful for the exploration of other novel two-mode band-edge oscillators, such as compact, high-power THz radiation sources for potential applications.

中文翻译：

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一种新型太赫兹前向和后向波双模带边振荡器

在本文中，提出了一种具有折叠波导的太赫兹振荡器的新型双模操作概念。为了演示这个概念，我们模拟并制造了一个双模式 4π 带边振荡器。仿真预测，设计的振荡器能够在 301.7-303 GHz 下为正向和反向操作模式提供超过 2 W 的最大输出功率。另一方面，测试数据显示，双模振荡器的第一个原型能够在大约 305.6 GHz（电压 23.04 kV）和 1.51 W（在 308.8 GHz（电压 24.33 kV）下产生超过 1 W 的输出功率，对于分别为前向和后向操作模式，与模拟相比，频移为 5–7 GHz。研究结果证明了所提出的用于开发新型双模带边振荡器的双模概念的正确性。测试和模拟之间存在一些不一致，将在文章中讨论。相信所提出的双模概念对于探索其他新型双模带边振荡器很有用，例如用于潜在应用的紧凑型高功率太赫兹辐射源。